I'd suggest installing this distribution block and lines in conjunction with others comments regarding pushrod length.
65-66 Dodge Mopar Dual Master Conversion Cylinder Block and Brake Lines Tubes | eBay
I've got a 2949033 Radiator. Galen's book says it's 28" and for a '69 Imperial, New Yorker or other C body with 440. Dont know much else about it.
Located in Arlington WA 98223
$100 plus the ride